DE102009041652B4 - Method for automatically landing an aircraft - Google Patents

Abstract

Method for automatically landing an aircraft, in particular an unmanned aerial vehicle, on a moving, in particular floating, landing platform such as an aircraft carrier, the aircraft being provided with automatic navigation devices and an automatic landing control device, comprising the steps of: a) determining the position data of one provided Landing point aboard the moving landing platform; b) determining movement data of a movement of the landing platform about its roll axis and / or its stamp axis; (c) determining at least one upcoming time when the landing point is a reference location and the landing platform is a reference location; d) transmission of the time point determined in step c) and the reference position of the landing point and / or the position and movement data determined in steps a) and b) and the reference orientation determined in step c) to the landing control device of the aircraft; e) control of the aircraft such that the location of the aircraft on the landing platform precalculated by the landing control device corresponds to the reference position of the landing point and that the landing time calculated by the landing control device corresponding to the time of reaching the Aufsetzortes corresponds to the time determined in step c) ,

Description

TECHNICAL AREA

The present invention relates to a method for automatically landing an aircraft, in particular an unmanned aerial vehicle on a moving, in particular floating, landing platform such as on an aircraft carrier. The invention further relates to a device for automatically controlling the landing of an aircraft on a moving landing platform.

STATE OF THE ART

Landing an aircraft on a moving landing platform, especially on an aircraft carrier, is already difficult with a manned, pilot-controlled aircraft. On the other hand, it is even more difficult to land an unmanned aerial vehicle on a floating landing platform, which is subject to constant wave motion. These undulations can occur around the transverse axis as so-called pounding or around the longitudinal axis as so-called rolling. With the combination of pounding and rolling, even a movement around the vertical axis of the floating landing platform can occur.

In addition, side wind influences, which can not be underestimated on the water, can make aircraft landing on a floating platform more difficult. Especially when landing remote-controlled unmanned aerial vehicles, crosswind influences are very difficult to compensate.

Through the described movements of the landing platform around its three spatial axes and possibly along its three spatial axes, the landing threshold provided on the landing platform, which defines the intended landing point, describes a constant movement around the spatial axes and possibly even along the spatial axes. This movement of the landing point presents a great difficulty in making a point-accurate landing since the landing aircraft must constantly be realigned.

Particularly with an aircraft carrier, which due to its length hardly performs any movements about its transverse axis, but which is subject to a noticeable rolling movement about its longitudinal axis due to the height of its structure, the position of the intended landing point as well as the angular position of the runway with respect to the longitudinal axis constantly fluctuates the frequency of the rolling motion. In conventional landing procedures, this causes the aircraft to fly in a lurching approach during constant approach, thereby increasing the risk of an imprecise landing or a landing crash or even a crash landing by the constant Nachkorrigieren the attitude of the landing aircraft.

In practice, therefore, first attempts by measures on board the aircraft carrier to compensate for the rolling movements of the ship. In addition, usually on an aircraft carrier near the landing point a landing control officer (LCO) is stationed, which has visual contact with the approaching aircraft and controls whether the aircraft is on the planned glide path and the pilot via radio and sign language correction signals for transmitted the aircraft situation. The landing of an aircraft on a moving platform, such as an aircraft carrier, is thus highly dependent on the capabilities of the aircraft crew and the crew of the moving platform, so that automatic landings, such as are preferred for unmanned aerial vehicles, so far are hardly feasible.

The US 2008 003 6654 A1 describes a method and a landing system for an aircraft on a ship, wherein the position and the velocity vector of the ship, ie the course of the ship, are determined by means of a satellite navigation device and wherein this data is transmitted to the approaching aircraft. A compensation of a movement caused by sea motion of the ship is not previously known from this citation.

PRESENTATION OF THE INVENTION

The object of the present invention is therefore to provide a generic method for automatically landing an aircraft on a moving landing platform, in which the safety during landing is significantly improved. Furthermore, a device suitable for carrying out such a method is to be specified.

The object of the method is achieved by the method specified in claim 1.

• a) Ermitteln der Positionsdaten eines vorgesehen Landepunktes an Bord der bewegten Landeplattform;
• b) Ermitteln von Bewegungsdaten einer Bewegung der Landeplattform um ihre Rollachse und/oder ihre Stampfachse;
• c) Bestimmung von zumindest einem bevorstehenden Zeitpunkt, an dem der Landepunkt eine Referenzlage und die Landeplattform eine Referenzausrichtung einnehmen;
• d) Übermittlung des im Schritt c) bestimmten Zeitpunkts sowie der Referenzlage des Landepunktes und/oder der in den Schritten a) und b) ermittelten Positions- und Bewegungsdaten und der im Schritt c) bestimmten Referenzausrichtung an die Landesteuerungseinrichtung des Luftfahrzeugs;
• e) Steuerung des Luftfahrzeugs derart, dass der von der Landesteuerungseinrichtung vorausberechnete Aufsetzort des Luftfahrzeugs auf der Landeplattform der Referenzlage des Landepunktes entspricht und dass der von der Landesteuerungseinrichtung vorausberechnete Aufsetzzeitpunkt, der dem Zeitpunkt des Erreichens des Aufsetzortes entspricht, dem im Schritt c) bestimmten Zeitpunkt entspricht.

In the inventive method for automatically landing an aircraft, in particular an unmanned aerial vehicle, on a moving, in particular floating, landing platform such as an aircraft carrier, the aircraft being provided with automatic navigation devices and an automatic landing control device, the following steps are carried out:

• a) determining the position data of a designated landing point on board the moving landing platform;
• b) determining movement data of a movement of the landing platform about its roll axis and / or its stamp axis;
• (c) determining at least one upcoming time when the landing point is a reference location and the landing platform is a reference location;
• d) transmission of the time point determined in step c) and the reference position of the landing point and / or the position and movement data determined in steps a) and b) and the reference orientation determined in step c) to the landing control device of the aircraft;
• e) control of the aircraft such that the location of the aircraft on the landing platform precalculated by the landing control device corresponds to the reference position of the landing point and that the landing time calculated by the landing control device corresponding to the time of reaching the Aufsetzortes corresponds to the time determined in step c) ,

ADVANTAGES

By predicting the time at which the landing point a defined reference position and the landing platform take a defined reference orientation, the movements of the landing platform can be ignored and the aircraft can make the landing approach with a constant attitude and on a substantially straight glide path. The landing control of the aircraft thus knows one or more future times at which the landing point on the landing platform will assume a defined reference position, and also knows the coordinates of this reference position (s) in an absolute coordinate system. The Landing Control may then choose the ground speed and the descent speed of the aircraft such that the touchdown point calculated from the current position of the aircraft, the ground speed and the descent speed and the height of the defined reference point of the landing point at the calculated point in time of the landing point in Room corresponds.

Since both the attitude of the aircraft and the landing platform's reference orientation are substantially coincident at the time the landing point and landing point coincide, at the moment of "touch-down," a smooth landing of the aircraft on the moving landing platform is predictable. This avoids a lurching of the aircraft in landing approach and keeping the course of the aircraft in landing approach is greatly facilitated, which is particularly beneficial for unmanned aerial vehicles. The method according to the invention is particularly effective because the spatial axis for which the motion data is determined in step d) is the roll axis (longitudinal axis) and / or the stamp axis (transverse axis) of the moving landing platform. As a result, the rolling motion of the landing platform and / or the pitch or pitching movement of the landing platform can be neutralized for the approach.

Further preferred and advantageous embodiment features of the method according to the invention are the subject matter of subclaims 2 to 7.

In a preferred variant of the method, an additional spatial axis for which the motion data are determined in step b) is the vertical axis of the moving landing platform, whereby a yawing motion of the landing platform can be neutralized.

Preferably, the reference position is at least approximately horizontal. As a result, the landing of the aircraft on the landing platform at a zero crossing of the corresponding rolling motion about the spatial axis (s), in particular about the roll axis, take place.

In a preferred embodiment of the method according to the invention, the side wind influences can be reduced by rotating the longitudinal axis of the runway provided on the movable landing platform before landing in the wind.

Preferably, this alignment of the landing platform takes place continuously during the approach of the aircraft.

In a further preferred development of the method according to the invention, translational motion data of the landing platform in the direction of at least one of the spatial axes are determined in step b) and taken into account in the determination of the time in step c) and these translational motion data are in step d) in the landing control device of Aircraft and taken into account in step e) in the control of the aircraft. As a result, in addition to neutralizing the movements of the landing platform about the spatial axes, a movement of the landing platform in the direction of one or more spatial axes can also be taken into account for the landing approach of the aircraft, and thus this movement can be neutralized.

The part of the problem relating to the device is achieved by the device having the features of claim 7.

The device for automatically controlling the landing of the aircraft on the moving landing platform, controls the landing of the aircraft according to a method of the invention based on position data provided on the landing platform landing point of movement data of the landing platform and / or a previously determined time at which the landing point Reference position, and also taking into account a given reference orientation of the landing platform at the reference time at which the landing point will assume the reference position. If the reference orientation is horizontal, for example, transversely to the approach direction, this ensures that the aircraft can land horizontally, ie at 0 ° roll angle.

The landing control of the aircraft knows - as has already been stated - one or more future times, at which the landing point on the landing platform will take a defined reference position, and also knows the coordinates of this reference position (s) in an absolute coordinate system. This data or the information required to compute this data is provided to the landing control via wireless data transmission from the landing platform. It also knows the current position of the aircraft in the absolute coordinate system. The landing control then selects the ground speed and sink speed of the aircraft so that the point of landing at the calculated time calculated from the current position of the aircraft, the ground speed and descent rate and the height of the defined reference point of the landing point correspond to the landing point.

Preferred embodiments of the invention with additional design details and other advantages are described and explained in more detail below with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Show it:

1 a schematic representation of the rolling movements of a moving landing platform on the example of an aircraft carrier;

2A and 2 B schematic representations of the geometric laws for describing the rolling motion of ships; and

3 the schematic representation of a landing approach to a floating landing platform.

PRESENTATION OF PREFERRED EMBODIMENTS

1 shows three phases of the rolling motion of a ship 1 as a floating platform using the example of an aircraft carrier with a view of the bow of the aircraft carrier. In the middle of the three representations is the ship 1 in the neutral position, that is, the roll angle is 0 ° and that the deck 10 of the ship 1 on which the runway is located is aligned with respect to the roll axis along a horizontal deck line H.

In the left illustration, the ship is clockwise viewed in the direction of travel by the angle α (in the illustration of FIG 1 , which is seen from the front of the ship, counterclockwise) rolled, so that the starboard side has lowered. The deck line H now runs at an inclination angle α to the horizontal deck line H. In the right-hand illustration, the ship has been rolled counterclockwise in the direction of travel by the angle -α, so that the port side has lowered there. The deck line H "now runs at the inclination angle -α to the horizontal deck line H. The total amount of the rolling movement of the ship is thus 2α.

2A and 2 B show the rolling motion of the ship 1 based on a geometric model. In 2A is the ship 1 in its neutral position, where the roll angle is 0 ° and the deck 10 of the ship is oriented horizontally. The axis of rotation D, around which the ship rolls, lies on the water surface, in the example of 2A thus at the intersection of the rolling axis enclosing vertical median plane 11 of the ship with the line 12 the surface level of the water level W. The center of gravity S of the ship and thus also the point of application A of the buoyancy force are in the neutral position of the 2A also in the middle plane 11 of the ship, so that both the buoyancy force acting on the point A, as well as the force acting on the center of gravity S weight of the ship 1 in the middle plane 11 of the ship 1 and thus cancel. The ship 1 lies calmly in the water, whereby it is assumed that the water is unmoved. The landing point L on the deck 10 provided runway is the amount h ₀ above the waterline.

Now the ship 1 in a rolling motion, as in 2 B is shown, the point of application of the buoyancy force shifts from that on the median plane 11 point A 'to the point A', at which the buoyancy force now acts and creates a righting torque around the metazentrum M. The geometric relationships correspond analogously to those of a rod pendulum with M as the suspension point.

In 2 B It can be seen that due to the rolling motion of the ship 1 around the angle α not just the angular orientation of the deck 10 opposite the neutral position in 2A has changed, but that too in 2A imagined landing point L on the deck 10 provided runway has moved by the amount x to the side and by the amount .DELTA.h up.

An aircraft on the lane of the deck 10 Thus, he wants his flight path to constantly adapt to the occurring during the rolling of the ship upward and downward movement of the landing point and to the respective lateral displacement and also adjust its attitude, that is the own roll angle so that it touches the roll angle of the Ship corresponds. Such a procedure, if it is feasible for a pilot at all, leads to a dangerous rolling course of the aircraft.

3 schematically shows the glide path G of a boat forming a moving platform 1 For example, an aircraft carrier, landing aircraft 2 , The ship 1 Floats on the water surface W and is a rolling motion, as in 1 and 28 is exposed exposed. The middle, evenly dashed representation 1A of the ship 1 shows the ship 1 in the in 2A shown neutral position with 0 ° roll angle and horizontal orientation of the deck 10 in relation to the roll axis. The upper irregular dashed line shows a representation 1B of the ship 1 under the action of a roll angle α, wherein the position of the ship shown therein 1 the in 2 B shown position corresponds. The landing point L 'on the deck 10 of the ship 1 in a position 1B lies above the landing point L in the neutral position 1A of the ship 1 , In a solid line, the situation 10 of the ship 1 at a roll angle of -α. It corresponds to the in 1 Ship position shown on the right. The landing point L '' is in this ship position 10 below the landing point L of the neutral position 1A of the ship 1 ,

The approaching aircraft 2 strives with its main landing gear 20 at the landing point L of the ship 1 sit up. As the aircraft should land horizontally in the direction of its transverse axis (ie, should not roll) for maximum buoyancy and optimum simultaneous contact of the two laterally spaced wheels of the main landing gear with the surface of the deck 10 of the ship 1 At the time of touchdown, the deck should also be guaranteed 10 in the transverse direction to the glide path G of the approaching aircraft 2 be aligned horizontally. This is in the in 2A shown neutral position of the ship 1 , the ship's representation 1A in 3 corresponds, the case. Ideally, therefore, both the ship should 1 as well as the landing aircraft 2 have a roll angle of 0 °.

In order to achieve this goal at least approximately, the following steps of the method according to the invention are carried out.

First, the ship 1 So the moving and moving landing platform, so turned around its vertical axis, that on the deck 10 intended runway with its landing direction in the wind is what is indicated by the arrows left in 3 is symbolized. This will ensure that the landing aircraft 2 in the landing approach is exposed to no or only minimal crosswind influences.

On board the ship 1 For example, via a satellite navigation system and / or an inertial navigation system, the exact position data of the landing point L, L ', L''on the deck 10 of the ship 1 as well as the movement data of the ship 1 motion detected with respect to a fixed (earth-fixed) coordinate system. As a result, at least one upcoming time is calculated at which the ship 1 his in 3 With 1A designated neutral position, the landing point L will thus be in its reference position at 0 ° roll angle and the landing platform will thus assume their reference orientation, namely with respect to the approach path G is aligned horizontally. This calculated time is via a fast datalink connection, indicated by the arrow 3 symbolized by the ship 1 to the approaching aircraft 2 transmitted and recorded there in the landing control device, for example in the on-board computer.

The aircraft now knows the reference position of the landing point L in the absolute, earth-fixed coordinate system, and at least one future point in time in which the landing point L will assume this reference position is the on-board computer of the aircraft 2 known. If it is assumed that the reference position of the aircraft carrier is also horizontal at this time, the on-board computer also knows this reference position. Otherwise, a corresponding reference position, which the ship will take at the future point in time, also via the fast data link connection 3 transferred from the ship to the aircraft and made available to the local on-board computer.

As the computer of the provincial control device of the aircraft 2 now knows the place and time at which the aircraft 2 on the deck 10 of the ship 1 The Land Control Facility may also be informed of the satellite navigation system or via a satellite navigation system an inertial navigation system determined current position of the aircraft 2 the aerodynamic control surfaces as well as the propulsion of the aircraft 2 so control the aircraft 2 moves on the glide path G and touches at the predicted time on the landing point L. For this purpose, the control of the aircraft takes place in such a manner that the landing place of the aircraft, which has been precalculated by the state control device, is placed on the deck 10 of the ship 1 corresponds to the reference position of the landing point (0 ° roll angle of the ship) and that the landing time preconditioned by the state control device, that is the time of reaching the Aufsetzortes, one of those located in the future times, at which the landing point his in 3 with L designated neutral position occupies. At this time, the aircraft will also assume an attitude that is substantially parallel to the given horizontal or to the via the data link 3 from the ship 1 to the aircraft 2 transmitted reference position of the lateral inclination of the deck 10 equivalent.

In this way, the aircraft can 2 without constant post-correction of one's own attitude essentially uninfluenced by crosswind and unaffected by a rolling motion of the ship 1 land.

Of course, not only the rolling motion of the ship can be achieved in this way 1 But also a movement of the ship about its transverse axis (pounding) or a movement of the ship about its vertical axis (yaw).

Flowing into the determination of the forthcoming time at which the landing point L will assume its reference position, not only the ship's movements around its three spatial axes but also translational movements of the ship along its three spatial axes, it is possible the aircraft 2 also reliable and safe on the ship 1 to land when it is driving or subject to drift. In this case, the position data of the landing point ascertained on board the ship for the upcoming landing time and preferably also the movement data of the ship or the landing platform along at least one of its spatial axes via the fast data link 3 to the on-board computer and thus to the landing control device of the approaching aircraft 2 transfer. The calculation of the forthcoming time at which the landing point will take the reference position (at 0 ° roll angle of the ship) and the absolute location of the landing point at that time with respect to a stationary Earth-fixed coordinate system or to the moving coordinate system of the aircraft 2 or the ship 1 can be carried out either aboard the aircraft or aboard the ship, with the results then optionally via the fast data link 3 between the ship 1 and the aircraft 2 can be transmitted.

The solution according to the invention of the above-mentioned problem is therefore based on the fact that the instantaneous landing point of the aircraft on the ship can be announced to the approaching aircraft at any time via a high-speed data connection. Due to the own speed known to the aircraft over the ground, the own altitude as well as the distance also known to the aircraft between the aircraft and the touchdown point, ie the landing point L, on the deck 10 of the ship 1 is the aircraft 2 At any time able to predict the expected time of arrival (estimated time of arrival) and thus the exact position of the own touchdown point. The control of the aircraft will then control the glide path G of the landing approach by influencing the descent and airspeed so that the pre-computed landing point coincides with the landing point when it assumes its reference position, ie when the ship's roll 1 is at zero crossing.

By comparing the wind direction information as well as the geographical difference in height between the aircraft 2 and the deck 10 of the ship 1 and the announcement of the ship's longitudinal axis or the orientation of the runway axis relative to the ship's longitudinal axis via the high-speed data connection 3 can the aircraft 2 safe on the deck like on a beacon 10 land of the ship.

The hardware components required for carrying out the landing method according to the invention are generally present both on the ship and in the aircraft, so that using these components only a corresponding flight guidance software on board the aircraft and a corresponding Rolllageberechnungssoftware on board the ship and a corresponding high speed Data transmission connection between the ship and the aircraft, preferably a line-of-sight data connection (direct line of sight connection between the ship and the aircraft) must be provided. Both on the ship 1 , as well as in the aircraft 2 As a rule, highly accurate positioning systems, for example satellite navigation systems, are available. Furthermore, at least on the ship 1 an inertial navigation system is required to accurately measure the current roll attitude of the ship; Such a system also usually belongs to the equipment of a ship, in particular of an aircraft carrier. Finally, an automatic speed and / or airspeed speed control system is needed on board the aircraft in order to be able to precisely comply with the expected time of arrival at landing point L. Also, such a cruise control system is generally present on board aircraft. Thus, the precision of landings of aircraft on moving platforms, in particular aircraft carriers or other suitable ships, can be improved with relatively little effort. Not only can it automate the landing, but it also makes it possible to make safe landings for remote unmanned aerial vehicles on such platforms.

Reference signs in the claims, the description and the drawings are only for the better understanding of the invention and are not intended to limit the scope.

LIST OF REFERENCE NUMBERS

1

ship

2

aircraft

3

Data Link Connection

10

deck

11

midplane

12

line

20

main landing gear

S

main emphasis

M

metacentre

H

deckline

G

glide path

W

water surface

L

landing point

L '

landing point

L ''

landing point

Claims (7)

Method for automatically landing an aircraft, in particular an unmanned aerial vehicle, on a moving, in particular floating, landing platform such as an aircraft carrier, the aircraft being provided with automatic navigation devices and an automatic landing control device, comprising the steps of: a) determining the position data of a designated landing point on board the moving landing platform; b) determining movement data of a movement of the landing platform about its roll axis and / or its stamp axis; (c) determining at least one upcoming time when the landing point is a reference location and the landing platform is a reference location; d) transmission of the time point determined in step c) and the reference position of the landing point and / or the position and movement data determined in steps a) and b) and the reference orientation determined in step c) to the landing control device of the aircraft; e) control of the aircraft such that the location of the aircraft on the landing platform precalculated by the landing control device corresponds to the reference position of the landing point and that the landing time calculated by the landing control device corresponding to the time of reaching the Aufsetzortes corresponds to the time determined in step c) , Method for the automatic landing of an aircraft according to claim 1, characterized in that in step b) additionally the movement data of a movement of the landing platform about the vertical axis of the moving landing platform are determined. A method for automatic landing of an aircraft according to claim 1 or 2, characterized in that the reference position is at least approximately horizontal. Method for the automatic landing of an aircraft according to one of the preceding claims, characterized in that in step b) also translational motion data of the landing platform in the direction of at least one of the spatial axes determined and taken into account in the determination of the time in step c) and that these translational motion data in step d) to the landing control device of the aircraft and taken into account in step e) in the control of the aircraft. A method for automatically landing an aircraft according to any one of the preceding claims, wherein the moving landing platform is movable, characterized in that the landing platform is aligned before the landing of the aircraft so that the longitudinal axis of the runway provided on the landing platform is turned into the wind, so Crosswind influences are minimized during landing. A method for automatic landing of an aircraft according to claim 5, characterized in that the alignment of the landing platform during the landing approach is carried out continuously. Device for automatically controlling the landing of an aircraft on a moving landing platform, the device being based on position data of a landing point provided on the landing platform, movement data of the landing platform and / or a previously determined Timing, where the landing point will occupy a reference position controls the landing of the aircraft according to a method according to any one of the preceding claims, wherein the control of the aircraft taking into account a predetermined reference orientation of the landing platform at the reference time at which the landing point will occupy the reference position takes place ,

Images